Free · Browser-Based · No Upload

Analyze Your Audio.
Instantly.

Drop any audio file — MP3, WAV, FLAC, AAC — and get BPM, integrated LUFS, musical key, peak level, dynamic range, and frequency spectrum in seconds. Everything runs in your browser. Your files never leave your device.

🥁 BPM Detection 📊 LUFS Measurement 🎵 Key Detection 📈 Frequency Spectrum 🎤 Mic Test 🔊 Tone Generator
Get Started →

What it does

Professional audio analysis in your browser

No software to install. No account required. Works with any audio file your browser can play.

🥁

BPM Detection

Detects tempo using spectral flux beat tracking on the kick-frequency band (below 140 Hz), with automatic octave correction for tempos from 62 to 180 BPM.

📊

Integrated LUFS

Measures loudness to the ITU-R BS.1770-4 standard with full K-weighting IIR filtering and gated integration. Compare directly against YouTube, Spotify, Apple Music, and EBU R128 targets.

🎵

Musical Key Detection

Builds a chromagram from the full audio buffer and correlates against Krumhansl–Schmuckler major and minor profiles to identify the musical key of your track.

📈

Frequency Spectrum

Real-time log-scaled spectrum analyzer with gradient rendering and labeled frequency axis. Bass, Mid, and Treble energy bands update live as your track plays.

🎤

Microphone Test

Real-time VU meter with peak hold, device name and sample rate detection, and a pass/fail signal checklist. Test any microphone or audio interface instantly.

🔊

Tone Generator

Generate sine, square, sawtooth, or triangle waves from 20 Hz to 20 kHz. Eight preset test tones for speaker frequency response and hearing range checks.

Who uses AudioLab

Built for anyone working with audio

From music producers checking their masters to podcasters hitting loudness targets — AudioLab gives you the numbers you need.

Music Production

Producers & Mixing Engineers

Check your mix's integrated LUFS before mastering, verify BPM when syncing samples, detect the musical key for harmonic mixing, and catch clipping before it reaches the master bus. Instant feedback without leaving the browser.

Podcast & Broadcast

Podcasters & Broadcasters

Verify your episode meets the −16 LUFS podcast standard or EBU R128 broadcast spec before uploading. Catch over-compressed or too-quiet audio before it goes live. The mic test checks your recording chain in seconds.

Live & DJ

DJs & Live Performers

Detect BPM and musical key for tracks in your crate. Use the tone generator to test speaker systems and PA response before a show. Check microphone signal and clipping levels at soundcheck.

Education & Research

Audio Students & Educators

Visualize frequency spectrum and oscilloscope waveforms for classroom demos. Explore how different audio formats, sample rates, and compression levels affect peak, LUFS, and dynamic range measurements.

Audio Analyzer

Drop any audio file — BPM, integrated LUFS, musical key, peak level, dynamic range, and frequency spectrum. All local, no upload.

🎵
Drop your audio file here
MP3 · WAV · FLAC · OGG · AAC
Processing runs entirely in your browser. Your audio never leaves your device.
track.mp3
0:00 / 0:00
Analyzing audio — computing LUFS, key, dynamic range…
BPM
—
beats / min
Integrated LUFS
—
K-weighted
Peak
—
dBFS max
Clipping
Clean
no clipping
Key
—
Dynamic Range
—
Sample Rate
—
Channels
—
Bass0%
Mid0%
Treble0%

Platform Loudness Standards

Microphone Test

Verify your mic is working before a call, recording, or stream. Tests signal quality, clipping, and device info.

○
Microphone detected
○
Signal present
○
No clipping
○
Sample rate OK
Device
—
Sample Rate
—
Level (RMS)
—

Tone Generator

Generate pure tones for speaker testing, headphone calibration, hearing range checks, and audio equipment verification.

440Hz
A4
20 Hz1001 kHz10 kHz20 kHz
30%
Quick Test Tones

Frequently Asked Questions

Everything you need to know about analyzing audio in your browser — BPM, LUFS, key detection, and more.

What is BPM and how is it detected?

BPM (Beats Per Minute) measures the tempo of a track. AudioLab detects BPM using spectral flux analysis on the low-frequency band (below 140 Hz) to isolate kick-drum transients, then calculates the median interval between beats. The result is corrected into the 62–180 BPM range by halving or doubling as needed.

What is LUFS and why does it matter?

LUFS (Loudness Units relative to Full Scale) is the standard used by streaming platforms to normalize audio loudness. Integrated LUFS represents the average perceived loudness of an entire track. Platforms like Spotify target −14 LUFS and YouTube targets −14 LUFS; exceeding these targets causes your track to be turned down automatically.

What are the platform loudness standards?

Each platform applies its own loudness normalization: YouTube −14 LUFS, Spotify −14 LUFS, Apple Music −16 LUFS, Podcasts −16 LUFS, and Broadcast (EBU R128) −23 LUFS. AudioLab shows your track's integrated LUFS alongside all targets so you can see at a glance whether your master meets the standard.

How does musical key detection work?

AudioLab builds a chromagram — a 12-bin pitch-class energy profile — from the decoded audio using a hand-rolled FFT. Each bin is correlated against the Krumhansl–Schmuckler major and minor key profiles. The key with the highest Pearson correlation coefficient is reported as the detected key.

What is dynamic range in audio?

Dynamic range is the difference between the loudest and softest parts of a track. AudioLab reports it as Peak dBFS minus Integrated LUFS. A higher value means greater contrast between quiet and loud sections. Over-compressed music can have a dynamic range below 6 dB; a well-mastered track typically sits between 8–14 dB.

What is audio clipping?

Clipping happens when a signal exceeds 0 dBFS — the maximum level a digital audio system can represent. The waveform is literally "clipped" flat at the ceiling, introducing harsh distortion. AudioLab counts samples that reach or exceed 0 dBFS and flags the track as clipping if any are found.

How does the microphone test work?

The Mic Test tab requests access to your microphone via the browser's Web Audio API. It displays a real-time VU meter with peak hold, shows the detected device name and sample rate, and runs a pass/fail checklist covering signal presence, clipping, and sample rate. No audio is ever recorded or sent anywhere.

What is the tone generator used for?

The Tone Generator produces pure sine, square, sawtooth, or triangle waves at any frequency from 20 Hz to 20 kHz. Common uses include speaker/headphone frequency response testing, hearing range checks, acoustic treatment verification, and equipment troubleshooting with calibrated test tones at standard frequencies (40 Hz, 100 Hz, 1 kHz, 10 kHz, 16 kHz).

Is my audio file uploaded to a server?

No. All analysis happens entirely inside your browser using the Web Audio API. Your audio file never leaves your device — there is no upload, no server processing, and no storage of any kind. This also means the tool works offline once the page has loaded.

Which audio formats are supported?

AudioLab supports any audio format your browser can decode — typically MP3, WAV, FLAC, AAC, OGG, and OPUS. Supported formats may vary slightly between Chrome, Firefox, and Safari. Files of any duration and sample rate are accepted; analysis is performed on the full decoded audio buffer.